illumos: manual page: ddi_log

DDI_LOG_SYSEVENT(9F) Kernel Functions for Drivers DDI_LOG_SYSEVENT(9F)

NAME

ddi_log_sysevent - log system event for drivers

SYNOPSIS

#include <sys/ddi.h>
#include <sys/sunddi.h>

int ddi_log_sysevent(dev_info_t *dip, char *vendor,
char *class, char *subclass, nvlist_t *attr_list,
sysevent_id_t *eidp, int sleep_flag);

INTERFACE LEVEL

illumos DDI specific (illumos DDI).

PARAMETERS

dip
A pointer to the dev_info node for this driver.

vendor
A pointer to a string defining the vendor. Third-party
drivers should use their company's stock symbol (or
similarly enduring identifier). Sun-supplied drivers should
use DDI_VENDOR_SUNW.

class
A pointer to a string defining the event class.

subclass
A pointer to a string defining the event subclass.

attr_list
A pointer to an nvlist_t, listing the name-value attributes
associated with the event or NULL if there are no such
attributes for this event.

eidp
The address of a sysevent_id_t structure in which the
event's sequence number and timestamp are returned if the
event is successfully queued. May be NULL if this
information is not of interest. See below for the
definition of sysevent_id_t.

sleep_flag
Indicates how a caller wants to handle the possibility of
resources not being available. If sleep_flag is
DDI_NOSLEEP, the caller does not care if the allocation
fails or the queue is full and can handle a failure
appropriately. If sleep_flag is DDI_SLEEP, the caller
wishes to have the allocation and queuing routines wait for
resources to become available.

DESCRIPTION

The ddi_log_sysevent() function causes a system event, of the specified
class and subclass, to be generated on behalf of the driver and queued
for delivery to syseventd, the user-land sysevent daemon.

The publisher string for the event is constructed using the vendor name
and driver name, with the format:

"<vendor>:kern:<driver-name>"

The two fields of eidp, eid_seq and eid_ts, are sufficient to uniquely
identify an event.

STRUCTURE MEMBERS

The structure members of sysevent_id_t are:

uint64_t eid_seq; /* sysevent sequence number */
hrtime_t eid_ts; /* sysevent timestamp */

RETURN VALUES

The ddi_log_sysevent() function returns:

DDI_SUCCESS
The event has been queued for delivery successfully.

DDI_ENOMEM
There is not enough memory to queue the system event at
this time. DDI_ENOMEM cannot be returned when
sleep_flag is DDI_SLEEP.

DDI_EBUSY
The system event queue is full at this time. DDI_EBUSY
cannot be returned when sleep_flag is DDI_SLEEP.

DDI_ETRANSPORT
The syseventd daemon is not responding and events
cannot be queued or delivered at this time.
DDI_ETRANSPORT can be returned even when sleep_flag is
DDI_SLEEP.

DDI_ECONTEXT
sleep_flag is DDI_SLEEP and the driver is running in
interrupt context.

ddi_log_sysevent supports the following data types:
DATA_TYPE_BYTE
DATA_TYPE_INT16
DATA_TYPE_UINT16
DATA_TYPE_INT32
DATA_TYPE_UINT32
DATA_TYPE_INT64
DATA_TYPE_UINT64
DATA_TYPE_STRING
DATA_TYPE_BYTE_ARRAY
DATA_TYPE_INT16_ARRAY
DATA_TYPE_UINT16_ARRAY
DATA_TYPE_INT32_ARRAY
DATA_TYPE_UINT32_ARRAY
DATA_TYPE_INT64_ARRAY
DATA_TYPE_UINT64_ARRAY

CONTEXT

The ddi_log_sysevent() function can be called from user, interrupt, or
kernel context, except when sleep_flag is DDI_SLEEP, in which case it
cannot be called from interrupt context.

EXAMPLES

Example 1: Logging System Event with No Attributes

if (ddi_log_sysevent(dip, DDI_VENDOR_SUNW, "class", "subclass",
NULL, NULL, DDI_SLEEP) != DDI_SUCCESS) {
cmn_err(CE_WARN, "error logging system event\n");
}

Example 2: Logging System Event with Two Name/Value Attributes, an Integer

and a String

nvlist_t *attr_list;
sysevent_id_t eid;

if (nvlist_alloc(&attr_list, NV_UNIQUE_NAME_TYPE, KM_SLEEP) == 0)
{
err = nvlist_add_uint32(attr_list, int_name, int_value);
if (err == 0)
err = nvlist_add_string(attr_list, str_name, str_value);
if (err == 0)
err = ddi_log_sysevent(dip, DDI_VENDOR_SUNW,
"class", "subclass", attr_list, &eid, DDI_SLEEP);
if (err != DDI_SUCCESS)
cmn_err(CE_WARN, "error logging system event\n");
nvlist_free(attr_list);
}

Example 3: Use Timeout to Handle nvlist and System Event Resource

Allocation Failures

Since no blocking calls are made, this example would be useable from a
driver needing to generate an event from interrupt context.

static int
xx_se_timeout_handler(xx_state_t *xx)
{
xx->xx_timeoutid = (xx_generate_event(xx) ?
timeout(xx_se_timeout_handler, xx, 4) : 0);
}

static int
xx_generate_event(xx_state_t *xx)
{
int err;

err = nvlist_alloc(&xx->xx_ev_attrlist, NV_UNIQUE_NAME_TYPE, 0);
if (err != 0)
return (1);
err = nvlist_add_uint32(&xx->xx_ev_attrlist,
xx->xx_ev_name, xx->xx_ev_value);
if (err != 0) {
nvlist_free(xx->xx_ev_attrlist);
return(1);
}

err = ddi_log_sysevent(xx->xx_dip, DDI_VENDOR_SUNW,
xx->xx_ev_class, xx->xx_ev_sbclass,
xx->xx_ev_attrlist, NULL, DDI_NOSLEEP);
nvlist_free(xx->xx_ev_attrlist);
if (err == DDI_SUCCESS || err == DDI_ETRANSPORT) {
if (err == DDI_ETRANSPORT)
cmn_err(CE_WARN, "cannot log system event\n");
return (0);
}
return (1);
}